Comparison of Lactulose and Compound Polyethylene Glycol Electrolyte Powder for Bowel Preparation before Colonoscopy ——A Single-Center Retrospective Cohort Study

Li Linqiang^*

Department of Gastroenterology, Tongxiang Hospital of Traditional Chinese Medicine

Abstract：

Objective To compare the bowel-cleansing efficacy, willingness to reuse the same regimen, and adenoma detection rate of lactulose versus compound polyethylene glycol electrolyte powder (PEG) for bowel preparation before colonoscopy. Method This single-center retrospective cohort study included 160 patients with complete records who underwent colonoscopy at Tongxiang Hospital of Traditional Chinese Medicine between January 2024 and December 2025. According to the bowel-preparation regimen actually received, patients were assigned to the lactulose group or PEG group (n = 80 each). Age and segmental and total BBPS scores were expressed as mean ± standard deviation and compared using independent-samples t tests. Sex, willingness to reuse the regimen, and adenoma detection rate were analyzed using the uncorrected Pearson chi-square test; Yates continuity correction and Fisher's exact test were added for the willingness-to-reuse outcome. Result Age and sex distribution did not differ significantly between the groups (both P > 0.05). Mean ± standard deviation scores in the lactulose versus PEG groups were 2.67 ± 0.61 versus 2.41 ± 0.63 for the left colon (t = 2.652, P = 0.009), 2.53 ± 0.73 versus 2.32 ± 0.47 for the transverse colon (t = 2.163, P = 0.032), 2.58 ± 0.50 versus 2.38 ± 0.49 for the right colon (t = 2.555, P = 0.012), and 7.78 ± 1.02 versus 7.12 ± 1.04 for total BBPS (t = 4.052, P < 0.001); all differences were statistically significant. The willingness-to-reuse rates were 96.3% (77/80) and 87.5% (70/80), respectively. The uncorrected Pearson chi-square test yielded P = 0.043, whereas Yates correction yielded P = 0.083 and the two-sided Fisher exact test yielded P = 0.079. Adenoma detection rates were 36.3% (29/80) and 32.5% (26/80), respectively, with no significant difference (χ2 = 0.249, P = 0.618). Conclusion In this single-center retrospective sample, the lactulose regimen was associated with higher BBPS scores. The between-group difference in willingness to reuse the same regimen was sensitive to the analytical method, and no significant difference in adenoma detection rate was observed.

Key Words：

lactulose; Compound Polyethylene Glycol Electrolyte Powder; colonoscopy; bowel preparation; Boston Bowel Preparation Scale (BBPS); patient acceptability